PHP feof Function
PHP feof function tutorial shows how to detect end of file in PHP. Learn feof with practical examples.
PHP feof Function
last modified April 3, 2025
The PHP feof function checks if the end of a file has been reached. It’s essential for reading files sequentially in PHP. The function returns true when the file pointer is at EOF.
Basic Definition
The feof function tests for end-of-file on a file pointer. It takes one parameter: the file pointer resource. Returns true if EOF is reached.
Syntax: feof(resource $stream): bool. The function is commonly used with file reading functions like fgets or fread.
Basic feof Example
This shows the simplest usage of feof to read a file line by line.
basic_feof.php
<?php
declare(strict_types=1);
$file = fopen(“example.txt”, “r”);
if ($file) { while (!feof($file)) { $line = fgets($file); echo $line; } fclose($file); }
This reads “example.txt” until EOF. The loop continues while feof returns false. Always close files with fclose after reading.
Reading Binary File
feof works with binary files using fread.
binary_file.php
<?php
declare(strict_types=1);
$file = fopen(“image.jpg”, “rb”); $buffer = “”;
if ($file) { while (!feof($file)) { $buffer .= fread($file, 8192); } fclose($file); }
// Process binary data in $buffer
This reads a binary file in 8KB chunks until EOF. The rb mode ensures proper binary reading on all platforms. Buffer size can be adjusted.
Error Handling
Proper error handling is important when using feof.
error_handling.php
<?php
declare(strict_types=1);
$filename = “nonexistent.txt”; $file = @fopen($filename, “r”);
if ($file === false) { die(“Cannot open file: $filename”); }
while (!feof($file)) { $line = fgets($file); if ($line === false) { break; // Handle read error } echo $line; }
fclose($file);
This shows proper file opening checks and read error handling. The @ suppresses warnings, but we explicitly check for failure. Always verify file ops.
CSV File Processing
feof can be used with CSV file processing.
csv_processing.php
<?php
declare(strict_types=1);
$file = fopen(“data.csv”, “r”);
if ($file) { while (!feof($file)) { $row = fgetcsv($file); if ($row === false) { continue; // Skip empty lines } print_r($row); } fclose($file); }
This reads a CSV file until EOF. fgetcsv returns false on empty lines or errors, so we skip them. Always handle potential CSV parsing issues.
Network Stream Example
feof works with network streams too.
network_stream.php
<?php
declare(strict_types=1);
$socket = fsockopen(“www.example.com”, 80); if ($socket) { fwrite($socket, “GET / HTTP/1.0\r\nHost: www.example.com\r\n\r\n”);
while (!feof($socket)) {
echo fgets($socket);
}
fclose($socket);
}
This reads an HTTP response until the server closes the connection. Network streams may behave differently than files. Timeouts and errors need handling.
Common Pitfalls
-
Premature EOF: Check for read errors before assuming EOF.
-
Memory Usage: Reading large files needs chunked processing.
-
Stream States: Some streams may not properly signal EOF.
-
Performance: Avoid calling feof in tight loops.
Source
This tutorial covered the PHP feof function with practical examples showing its usage with different file types and streams.
Author
My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.
